No limit to amounts of times you can reapply and no 30 day window in between applications. Pretty much score driven. Apply when you know your scores are high. Pretty much the secret. Well...there's a lot more to it depending on your credit situation. If you have high risk lender as a mortgage provider or if you have had recent credit activity which is alarming...even with a high score you can be declined. But those instances are few and far between.